Cleavable Ortho Ester Type Surfactants

Abstract With the focus on quaternary ammonium compounds, this paper describes how the ortho ester chemistry can be used as a versatile tool for synthesis of cleavable surfactants of various types. This class of chemodegradable surfactants hydrolyzes rapidly under mild acidic conditions at the same time as they are long-term stable in alkaline aqueous solutions. Further, the rate of cleavage can be modified by varying the structure of the surfactant. An additional feature is the possibility to design surface active compounds that release a daughter surfactant with different properties upon cleavage. Ortho ester-based surfactants could be of use in a large number of applications as exemplified in the paper. Good biodegradation data are of importance for virtually all types of surfactants nowadays. However, there actually seem to exist very few, if any, investigations regarding the biodegradation of cleavable surfactants under both hydrolytical and non-hydrolytical conditions. Data from the initial part of such a study on cationic ortho ester surfactants are presented and discussed in this paper. The results strongly indicate rapid biodegradation for this class of compounds under varying conditions.